Osteomyelitis Risk in Patients With Transfemoral Amputations Treated With Osseointegration Prostheses

Abstract

BackgroundPercutaneous anchoring of femoral amputation prostheses using osseointegrating titanium implants has been in use for more than 25 years. The method offers considerable advantages in daily life compared with conventional socket prostheses, however long-term success might be jeopardized by implant-associated infection, especially osteomyelitis, but the long-term risk of this complication is unknown.Questions/Purposes(1) To quantify the risk of osteomyelitis, (2) to characterize the clinical effect of osteomyelitis (including risk of implant extraction and impairments to function), and (3) to determine whether common patient factors (age, sex, body weight, diabetes, and implant component replacements) are associated with osteomyelitis in patients with transfemoral amputations treated with osseointegrated titanium implants.MethodsWe retrospectively analyzed our first 96 patients receiving femoral implants (102 implants; mean implant time, 95 months) treated at our center between 1990 and 2010 for osteomyelitis. Six patients were lost to followup. The reason for amputation was tumor, trauma, or ischemia in 97 limbs and infection in five. All patients were referred from other orthopaedic centers owing to difficulty with use or to be fitted with socket prostheses. If found ineligible for this implant procedure no other treatment was offered at our center. Osteomyelitis was diagnosed by medical chart review of clinical signs, tissue culture results, and plain radiographic findings. Proportion of daily prosthetic use when osteomyelitis was diagnosed was semiquantitatively graded as 1 to 3. Survivorship free from implant- associated osteomyelitis and extraction attributable to osteomyelitis respectively was calculated using the Kaplan-Meier estimator. Indication for extraction was infection not responsive to conservative treatment with or without minor débridement or loosening of implant.ResultsImplant-associated osteomyelitis was diagnosed in 16 patients corresponding to a 10-year cumulative risk of 20% (95% CI 0.12–0.33). Ten implants were extracted owing to osteomyelitis, with a 10-year cumulative risk of 9% (95% CI 0.04–0.20). Prosthetic use was temporarily impaired in four of the six patients with infection who did not undergo implant extraction. With the numbers available, we did not identify any association between age, BMI, or diabetes with osteomyelitis; however, this study was underpowered on this endpoint.ConclusionThe increased risk of infection with time calls for numerous measures. First, patients should be made aware of the long-term risks, and the surgical team should have a heightened suspicion in patients with method-specific presentation of possible infection. Second, several research questions have been raised. Will the surgical procedure, rehabilitation, and general care standardization since the start of the program result in lower infection rates? Will improved diagnostics and early treatment resolve infection and prevent subsequent extraction? Although not supported in this study, it is im...

Analysis of the Stomal Microbiota of a Percutaneous Osseointegrated Prosthesis: A Longitudinal Prospective Cohort Study

“…It is interesting to note that our observation of a significant benign presence of S. aureus within the stoma (Fig. ), correlates with other clinical studies reporting S. aureus as one of the most common bacteria found in superficial and deep cultures obtained from infected POP patients . These data indicate a potential for S. aureus to move from apparent commensal to become an opportunistic pathogen under the conditions mentioned above.…”

“…Although most percutaneous OI devices used today differ in implant design, device materials, surface methods of osseointegration, means of skin attachment, surgical implantation techniques, time to full ambulation, modes of mechanical failure, aseptic loosening, and stress shielded bone resorption, these systems share a single commonality in that they all require an opening in the skin, referred to as “the stoma,” through which an artificial limb is connected to the appendicular skeleton . Clinical reports indicate that most of these percutaneous devices become infected one or more times during their lifetime and that these infections are usually superficial and readily treated with appropriate oral antibiotics …”

“…Specific data on the rates of significant infections in the European patient populations vary between centers and surgical techniques, but range between 0% and 50% and usually include both superficial and deep infections . In two European studies, deep infections with bone necrosis and osteomyelitis were observed, but the incidence was low and varied between 0.05% and 0.16%. A more recent clinical cohort series reported a complete absence of stomal infection in 31 patients with 33 implants in place for up to 4 years, using only mild soap and daily shower hygiene …”

Systematic review of the safety and efficacy of osseointegration prosthesis after limb amputation

“…The patients in the latter studies overlapped with those in another study already included in the review. The remaining 22 articles comprising 13 unique studies met the inclusion criteria and were included in the review.…”

Cancer Metastases to Bone: Concepts, Mechanisms, and Interactions with Bone Osteoblasts

“…Osteomyelitis is a severe bone infection, typically caused by the bacterium Staphylococcus aureus , which, if left untreated, can lead to patient death [ 36 , 37 ]. In adults, S. aureus infection and subsequent osteomyelitis are typically associated with surgical osseointegration implants (e.g., femoral implants [artificial hip] or dental implants) [ 38 , 39 , 40 ]. Interestingly, S. aureus is highly adapted to specifically interact with bone osteoblasts as a result of microbial surface components recognizing adhesive matrix molecules, namely bone sialoprotein, osteopontin, type I collagen, fibronectin, and integrin alpha 5 beta 1 [ 29 , 41 ].…”